add dtls tunnel

listener/dtls/listener.go

@@ -0,0 +1,98 @@
+package dtls
+
+import (
+	"context"
+	"crypto/tls"
+	"net"
+	"time"
+
+	"github.com/go-gost/core/listener"
+	"github.com/go-gost/core/logger"
+	md "github.com/go-gost/core/metadata"
+	admission "github.com/go-gost/x/admission/wrapper"
+	xnet "github.com/go-gost/x/internal/net"
+	"github.com/go-gost/x/internal/net/proxyproto"
+	climiter "github.com/go-gost/x/limiter/conn/wrapper"
+	limiter "github.com/go-gost/x/limiter/traffic/wrapper"
+	metrics "github.com/go-gost/x/metrics/wrapper"
+	"github.com/go-gost/x/registry"
+	"github.com/pion/dtls/v2"
+)
+
+func init() {
+	registry.ListenerRegistry().Register("dtls", NewListener)
+}
+
+type dtlsListener struct {
+	ln      net.Listener
+	logger  logger.Logger
+	md      metadata
+	options listener.Options
+}
+
+func NewListener(opts ...listener.Option) listener.Listener {
+	options := listener.Options{}
+	for _, opt := range opts {
+		opt(&options)
+	}
+	return &dtlsListener{
+		logger:  options.Logger,
+		options: options,
+	}
+}
+
+func (l *dtlsListener) Init(md md.Metadata) (err error) {
+	if err = l.parseMetadata(md); err != nil {
+		return
+	}
+
+	network := "udp"
+	if xnet.IsIPv4(l.options.Addr) {
+		network = "udp4"
+	}
+	laddr, err := net.ResolveUDPAddr(network, l.options.Addr)
+	if err != nil {
+		return
+	}
+
+	tlsCfg := l.options.TLSConfig
+	if tlsCfg == nil {
+		tlsCfg = &tls.Config{}
+	}
+	config := dtls.Config{
+		Certificates:         tlsCfg.Certificates,
+		ExtendedMasterSecret: dtls.RequireExtendedMasterSecret,
+		// Create timeout context for accepted connection.
+		ConnectContextMaker: func() (context.Context, func()) {
+			return context.WithTimeout(context.Background(), 30*time.Second)
+		},
+		ClientCAs:  tlsCfg.ClientCAs,
+		ClientAuth: dtls.ClientAuthType(tlsCfg.ClientAuth),
+	}
+
+	ln, err := dtls.Listen(network, laddr, &config)
+	if err != nil {
+		return
+	}
+	ln = metrics.WrapListener(l.options.Service, ln)
+	ln = proxyproto.WrapListener(l.options.ProxyProtocol, ln, 10*time.Second)
+	ln = admission.WrapListener(l.options.Admission, ln)
+	ln = limiter.WrapListener(l.options.TrafficLimiter, ln)
+	ln = climiter.WrapListener(l.options.ConnLimiter, ln)
+
+	l.ln = ln
+
+	return
+}
+
+func (l *dtlsListener) Accept() (conn net.Conn, err error) {
+	return l.ln.Accept()
+}
+
+func (l *dtlsListener) Addr() net.Addr {
+	return l.ln.Addr()
+}
+
+func (l *dtlsListener) Close() error {
+	return l.ln.Close()
+}

listener/dtls/metadata.go

@@ -0,0 +1,12 @@
+package dtls
+
+import (
+	mdata "github.com/go-gost/core/metadata"
+)
+
+type metadata struct {
+}
+
+func (l *dtlsListener) parseMetadata(md mdata.Metadata) (err error) {
+	return
+}